CHOICES: Batteries

I was looking around for some specs for battery terminal torque specs and came upon this chart at the MK Battery site:

I'm about to start my seventh season with the four 8A4D AGM batteries that make up my 48 volt electric propulsion bank. Somehow I instinctively used them in a way that should provide over a thousand life cycle charges.  I typically revert to Hybrid mode using the Honda 2000i generator once the battery bank has dropped to 70 to 80% from 100% full charge.  Turns out that looks like a good point to have a good charge life cycle for the bank.  So far so god. I still think I made the right decision in going with AGM batteries over the Lithium Ion batteries that were still fairly new back in 2008 when I did the conversion. The cost and availability were factors I considered. Today I think I would still go with the AGM's as they seem to be holding up well. I'll do some more in depth battery testing in a few weeks to see how well.    The following video is and example of my modus operandi using electric propulsion and when I operate in hybrid mode on an unusually windless day heading down the Hudson River: